The check valve of U.S. Pat. No. 5,033,503 on which I am a co-inventor sold by Check-All Valve, Mfg. Co., Des Moines, Iowa, has been very successful. In food processing, however, modifications to this valve when used in sanitary tubing are needed that will minimize cracks and crevices where microbal and bacterial growth may occur and for ease of cleaning and sterilization.